Ok heres what is on the bike for performance now... full boz bros exhaust (no baffle), K&N filter and power commander. I still need to map the power commander. My question is should i use the mapping off the dynojet website or would i gain that much more by getting a custom map by a dealer with a dyno (it's $275 for a custom map). I was thinking about getting velocity stacks also (is it worth the money?). The boz bros exhaust sounds awesome but don't think it does much for performance. I have the stock headers and a yoshi pipe also. Would I gain that much more power by switching to that exhaust setup verses leaving the boz bros on? Any input or more ideas are much appreciated.

>should i use the mapping off the dynojet website or would i gain that much more by getting a custom map by a dealer with a dyno (it's $275 for a custom map).

You may not get any gains by using a downloaded map. They are a crapshoot at best, even if they are said to be specific for your bike setup.

>I was thinking about getting velocity stacks also (is it worth the money?).

The general consensus is no. A very slight top end gain at the expense of midrange.

>The boz bros exhaust sounds awesome but don't think it does much for performance. I have the stock headers and a yoshi pipe also. Would I gain that much more power by switching to that exhaust setup verses leaving the boz bros on? Any input or more ideas are much appreciated.

I don't know about that exhaust specifically, but in general, most aftermarket full exhaust systems have larger pipes and have optimal scavenging at a higher RPM than a stock exhaust, meaning you lose some low end and midrange torque to get higher top speed HP. Also, since a full exhaust system increases airflow and changes the air/fuel mixture, you have to have the A/F map changed accordingly. So, if you are running a full system on a stock ECU or untuned Power Commander, it might well run like a dog. Reverting to your stock system will probably make your bike feel more powerful in the RPM range where you run it most.

In any case, do all the mods (exhaust, air filter, cams, thinner gasket, or anything else that changes the air flow) before you get the bike tuned. As you can see it's pricey but a custom tune is the only way you can realize the performance of those types of modifications.

I had a custom map done on my 01 750 3 years ago. Here is what I have on her: K&N air filter, TRE, Yosh carbon slip on, and velocity stacks. She had major kick down low and mid range. The engine was blown last june because of the wrong type spark plugs. I brought an 05 750 that same month. She has the same equipment expect for a BMC air filter and no velocity stacks. I finally got an engine for my 01 and took her for a spin yesterday. The custom map was still in the ECU. She has more power in the low and mid range than the 05!!!! The custom map is the way too go no doubt.